Question

give reason :
1) often silver jewellery become black
2) unused copper articles becomes greenish
(please answer in long answer type question)
please take a look in this sentence​

Answer 1

Answer:

1) Silver becomes black because of hydrogen sulfide (sulfur), a substance that occurs in the air. When silver comes into contact with it, a chemical reaction takes place and a black layer is formed. Besides that, the natural oils that your skin produces can also react to your silver jewelry.

2) Copper metal when exposed to air turns green in colour due to corrosion. When copper vessel is exposed to air in rainy season, the metal reacts with gases and moisture and atmospheric gases to form a mixture of copper carbonate and copper hydroxide. This gives a green colour to the surface of copper metal.